The Coast Guard has called off a search for a missing sailor whose boat was spotted drifting off Shippan Point in Stamford Saturday.

Witnesses say they saw David McKinley take out his 21-foot Catalina sailboat Saturday morning, but then discovered the boat floating in the Long Island Sound without him. According to the Coast Guard and investigators, the search area is at least 25 square miles.

Friends and fellow boaters say McKinley was an avid safety-conscious sailor. Investigators say evidence found on McKinley's boat and his past focus on boating safety point to the possibility of a suicide.